The program has been updated on GitHub to fix this problem for Raspberry Pi.
Let me know if you still see a problem after an update. You should be able to update the program from Plugins > System Update.
I will add some documentation about the rain sensor pin to the SIP wiki on GitHub. There are a few different hardware configurations that SIP works with such as Raspberry Pi, Beagle Bone Black, Raspberry Pi with an OpenSprinkler board, etc. which would make it difficult to add the information to the tool tip on the Options page.
Dan
Let me know if you still see a problem after an update. You should be able to update the program from Plugins > System Update.
I will add some documentation about the rain sensor pin to the SIP wiki on GitHub. There are a few different hardware configurations that SIP works with such as Raspberry Pi, Beagle Bone Black, Raspberry Pi with an OpenSprinkler board, etc. which would make it difficult to add the information to the tool tip on the Options page.
Dan